French security forces deployed Thursday in a northern town where two brothers suspected of having gunned down 12 people in an Islamist attack on satirical magazine Charlie Hebdo abandoned their car, a police source said.

RAID, the anti-terrorist unit of the French police force, and the GIGN, a paramilitary special operations unit, deployed in Villers-Cotterets in the northern Aisne region “where a car was abandoned after being used by the two suspects, who were identified by a witness,” the source told AFP.

Cherif Kouachi, 32, a jihadist well-known to police, and his brother Said, 34, were spotted by the manager of a petrol station in the town about an hour’s drive northeast of Paris, who after being robbed “formally identified” the two men.

They were described as “masked, with Kalashnikovs” and what appeared to be a rocket-launcher.